Tire tread



Oct. 11, 1932- J. JARVIS 1,882,498

TIRE TREAD Filed Jan. 3. 1929 gwwmtoz rem .1;

Patented Oct. 11, 1932 UNITED STATES PATENT orrics p or rum,

J'ABVIS, OI PALKER, MASSACHUSETTS,ASSIGNOB TO JARVIS ll; JARVIS, INC

IASSACHUSE'ITS, A CORPORATION OF MASSACHUSETTS Application filed January 3, 1928. Serial 1T0. 380,015.

This invention relates to improvements in tires and particularly to combination demountable tires for casters and wheels of similar description and to an improved process for making such tires. 8

The principal object of the invention is to provide an improved replaceable tire having a relatively thin cushion tread and a relatively rigid base or support to insure a minimum of traction friction and a maximum ease of replacement.

Another object of the invention is to provide an improved process for making a replaceable tire having a relatively thin cushi on tread and relatively rigid support thereror.

Another object of the invention is to provide improved means for making a cushion tire of relatively small traction friction.

Another object of the invention is'to provicle an improved combination tire having a relatively thin cushion tread and a relatively rigid attaching base.

Another object of the invention is to pro vide a simple ehlcient and inexpensive re placeeble tire oi low traction inaction with a maximum of ease in installing and re-.

placing.

@ther ob ects and advanta es of the invention will become apparent from the following description taken in connection with the accompanying drawing. It will be apporent that many changes in the arrangement of parts and details of construction and steps of the process may be made Without depart ing from the spirit of the invention as expressed in the accompanying claim. L therefore, do not wish to be limited to the exact arrangements shown and described as the preferred forms only have been shown by way of illustration.

m: of Fig. I; and

Referring to the drawing: Fig. I is a front view of a wheel with the invention in place thereon;

- Fig. 11 is a cross section on line H-H of Fig. I;

Fig. III is a cross sectionof a inodified form of the invention taken on line 11-11 Fig. IV is a view similar to Fig. III of another modification.

Previous to my invention rubber tires for double disk wheels have occupied the entire space from the bottom of the tire chamber between the disks to the outer periphery of the tire. This has made a relatively thick and heavy rubber tire embodying a large amount of compressibility which increased the traction friction considerably as heavy vantages of a rubber tire end overcomes the disadvantages of high traction friction and which also may be easily replaceable.

7 Referring to the drawing wherein similar reference characters are used to denote corresponding parts throughout. I provide a tire base 1 having the recesses 2 to engage the projecting flanges 3 of the double disks i of a se arable Wheel member 5. lhe disks lare hel together by the bolts 6 in the usuel man nor. The tire base 1 is relativelv resilient or compressible as compared with the disks 4. The disks i are usually of metal. I mey make my tire base i of hard. rubber or composition as shown in Fig. 1V. or of Wood as shown inFig. Ill, or of a composition or fiber as shown in Fig. ll wherein is embodied cords vor pieces of fibrous meterial 7. lhe tire hasei must be compressible enough to be engaged and held tightly by the flanges 3 of the disks 4 so it will not slip. Around the outer peripherv of the tire base 1 I place the thin rubber tire or band 8 of the usuel soft rubber or resilient materiel. The resilient tire trend or band 8., being relatively thin, forms a minor part of the entire tire. The tire 8 is relatively resilient or compress ible as regards the tire base 1. l vulconize or cement or otherwise secure the tire 8 to the tire base 1 at 9 so that. the parts 1 and 8 joined by the uniting medium 9 form a unitaryreplaceable tire element. To place a element on the wheel the flanges 3 of the disks 4 are placed'in the grooves 2 of the tire base 1 and the disks bolted together by the bolts 5 6. To replace a worn tire it is necessary only to loosen the bolts 6, insert the new t1re element between the disks 4 as described above and tighten the bolts '6. It .is also apparent that if the tire 8 is secured to the tire base 1 by cementing or other similar means, it may be stripped off when worn and replaced with a new ringer tire tread. I This construction provides a thin compressible tire 8, whose traction friction is low, 15 secured to a relatively-rigid tire base 1 that is relatively compressible with respect to the disks 4 so that it may be tiahtlv clamped and held in place, thus providing an easily replaced tire of low traction friction yet re- 20 taining all the desirable features of a soft tread.

From the foregoing description it will be be seen that I have provided simple, eficient Y and inexpensive means for obtaining all of the objects and advantages of the invention. Having described my invention, I claim: In a device of a character described, a relatively hard wheel center having a peripheral tire supporting portion and tire in- :w terengaging means thereon, a tire on said tire supporting portion having a hard annular tire base of a lower degree of hardness than said wheel center and surrounding said wheel center, said tire base having a V shaped as inner surface in direct engagement with the tire supporting portion substantially throughout its surface area, said tire base also having substantially flat parallel side walls with diametrically opposed circular grooves w therein interengaging with the tire interengaging means on the wheel center and preventing displacement of the V shaped inner surface from the tire supporting portion and having a substantially flat peripheral surface 4 lying substantially parallel with the axis of the Wheel center, and a separate relatively soft and resilient annular tire tread of sub- Stantially rectangular shape cross section having its inner broad surface secured to the substantially flat peripheral surface of the tire base and having its side walls lying substantially in the plane of the side walls of said tire base, the cross sectional area of the soft tire tread being less than the cross sectional area of the tire base.

FRANK J. JARVIS. 

